What is the best way to rig a robot?
Your question is a bit vague, but I think from whre you are you have 2 main solutions: either keep all these meshes as separate objects, or join them all into one object.
Separate objects : In this case, select the part, shift select the armature, switch it to Pose mode, select the right bone, and press CtrlP &gt; (Set Parent To) Bone.
One object: In this case, select the whole object, shift select the armature and press CtrlP &gt; (Set Parent To) With Empty Groups. Then you need to select each part of your object in Edit mode and assign it to the right vertex group (the one that has the name of the bone that is supposed to control it) in the Properties panel &gt; Object Data &gt; Vertex Groups.